Demonstrators chanted ‘Turkish state, fascist state’ and waved banners branding him a terrorist. He has been accused of purging opponents, sacking thousands of officials and jailing critics and journalists.

Mrs May shook hands and posed for photographs with Mr Erdoğan outside No.10, yards from the protests in Whitehall.

Earlier, Mr Erdoğan had an audience with the Queen at Buckingham Palace on the last of his three days in Britain. He used the Downing Street meeting to accuse Israel and the US over a ‘horrible massacre’ in Gaza.